What is the ruling on reading the Qur’an without ablution for memorization and learning, and what are the opinions of the four Imams and scholars on this matter?

It is permissible for a person in minor ritual impurity (hadath asghar) to recite the Quran, though it is preferable for him to be in a state of ablution (wudu). It is forbidden for a person in a state of ritual impurity (muhdith) to touch or carry the Mushaf (copy of the Quran) according to the majority of scholars. They have adduced as proof the words of Allah Almighty: "None touch it except the purified" (Quran 56:79), and what the Prophet, peace and blessings be upon him, wrote to Amr ibn Hazm: "That none should touch the Quran except one who is pure." It is permissible for a person in a state of ritual impurity to read from the Mushaf without touching it. Exceptions to this are made for children due to necessity, and carrying the Mushaf as part of one's belongings if it is not the primary purpose of carrying them.